FANS – The Future is Here

In the early 1980s ICAO began to recognise the need for major improvements to the air navigation system to take civil aviation into the 21st century. In 1983, ICAO established the special committee on Future Air Navigation Systems with the task of studying, identifying and assessing new concepts and new technology and making recommendations for the coordinated evolutionary development of air navigation over a timescale of the order of 25 years.

The FANS committee concluded that the exploitation of satellite technology is the only viable path that will overcome present limitations and meet future needs on a cost-effective global basis. However, FANS recognised that some line-of-sight systems would continue to be appropriate where their propagation limitations were not a problem, such as VHF communications and SSR Mode S in terminal areas. The FANS concept is a sensible mix of satellite technology and the best of the line-of-sight systems to achieve an overall optimum result.

FANS is particularly relevant in the Asia-Pacific region where traffic is expected to double in the next decade. The International Air Transport Association (IATA) has warned that air traffic growth could be held back by the existing ground based air navigation systems. It has said that the cost of a 747 idling on a runway for one minute every hour costs the world economy one million dollars per annum.

Qantas led the push in gathering a group of major airlines, plus Boeing and Honeywell, in a formal FANS project. Its position was simply that if it didn’t start the ball rolling on a single global ATM system, it may be years before the CNS/ATM technology is properly introduced. In the meantime airlines would continue to accumulate annual losses of millions of dollars as airways congestion worsens.

In 1993, Qantas assembled a small consortium of Pacific operators including Air New Zealand, Cathay Pacific and United Airlines, all of whom stand to benefit from FANS implementation in the Asia-Pacific region. Together they approached Boeing and Honeywell to revive an earlier attempt by Boeing (avionics package B, ditched in 1992) and modify it to make it a cost effective package.

United Airlines had already participated in the Pacific Engineering Trials and analysed the human factor requirements for ATC datalink operations, developed the re-analysis and rerouting of aircraft with Dynamic Aircraft Route Planning System (DARPS) and engineered the operational implementation of Automatic Dependent Surveillance (ADS).

The main aims in modifying the existing flight management system (FMS) involves the reduction of errors generated by navigation deviations or ‘blunders’; the elimination of transmission and interpretation errors by using datalink; and the introduction of ADS.

In May 1993 a meeting of the Informal South Pacific ATC coordinating group (ISPACG) appointed a working group to define ATC procedures, operational benefits and interoperability requirements of satellite-aided ATC. The region’s aviation regulatory bodies, also members of ISPACG, committed the funds to install the necessary infrastructures in Australia, the US west coast, New Zealand and Fiji. In the aircraft, the Boeing FANS-1 package was to be the catalyst for the implementation.

In June 1994 Qantas provided a 747-400 to Boeing for a series of trials of FANS-1 equipment on normal commercial Pacific routes. For Boeing, who had no aircraft available for the trials, the certification programme was the first to be carried out away from its Seattle base.

The “complete” FANS-1 integrated system comprises: A flight management computer (FMC) update; Satellite communications capability (Satcom); A datalink system upgrade which will also support ADS and pilot/controller datalink communications (CPDLC); Turin GPS units; A flight deck printer.

Airbus has announced a similar package, called FANS-A, for its A330 and A340 aircraft. McDonnell Douglas is reportedly working closely with airline representatives to define a simpler, GPS based architecture that could be used on the MD-11 and retrofitted to other commercial aircraft.

In supporting the Qantas initiative in the FANS-I project, CASA’s chief technical adviser and chairman of ICAO’s FANS committee, Brian O’Keeffe said, “Using satellites, FANS will transform air traffic control, aircraft navigation and communications, solve the problems of growing airways congestion and provide airlines with a huge operational cost savings.” Mr O’Keeffe recently won the prestigious Aerospace Laurel by US trade magazine Aviation Week and Space Technology for his leadership and visionary role in creating FANS.

A study undertaken in early 1993 showed Qantas was incurring costs of $4 million a year through penalties of altitude. Often flights couldn’t make their scheduled destinations. According to Captain David Massy-Greene project, manager for Qantas, “It comes down to simple accounting. The less fuel we burn the quicker the journey, reducing the operating, maintenance and crewing costs and maximising payloads”.

But Qantas sees FANS not only beneficial on the Pacific routes. According to Massy-Greene, “on a proposed flex track from Bangkok to Europe via China and Russia, and subject to approval from the relative authorities, a saving of up to 49 minutes could be achieved. This was not previously thought possible before.

Qantas is suffering badly on the European route because of the volume of traffic leaving Asia every night. The Bay of Bengal has been a choke point for many years and Qantas uplifts about 10 tonnes of extra fuel every night at Bangkok to avoid having to make a technical stop en route to London.

Massy-Greene is very passionate about this project and FANS in general. Since taking on the project on behalf of Qantas he has been overwhelmed by the enormous potential FANS has to offer.

“We are only scratching the surface. FANS is the most significant step in the aviation industry since the invention of radar. It’s important that we recognise it’s value and get behind what should be a global push towards future air navigation.”

Final FANS-1 certification took place on June 20 and, the very next day, Qantas flew a revenue flight to Los Angeles using the technology. Figures from the flight are currently being analysed by Qantas along with the figures from the normal Sydney/Los Angeles route, to establish fuel cost savings. Despite flying a greater distance over the earth’s surface, a typical FANS trip from Sydney to Los Angeles could represent a saving of up to 30 minutes. This is quite significant when you consider a 747 can burn up to 182kg (400lb) of fuel every minute.

Massy-Greene was earlier this year awarded the first Global Navcom Laurel for his outstanding contribution to the development of the Future Air Navigation System. The award, by the Global Navcom Program Committee, is sponsored by IATA and the United Nations through ICAO.

Three aircraft from Qantas’ Pacific fleet are already FANS-1 equipped and the remainder are expected to be by mid October. In the near future, when more FANS equipped aircraft are flying the Pacific routes, reduced separation standards can be demonstrated which will further enhance the total FANS concept. One 747-400 from the Qantas European fleet is being prepared to demonstrate FANS capabilities particularly in the Indian, China and the southern Russian regions.

At the same time United will be making use of its Dynamic Aircraft Rerouting Planning System (DARPS). This allows individual airlines to negotiate with ATC after the flight has commenced to reroute their aircraft onto the best tracks based on updated weather information.

DARPS works like this:

1. Aircraft departs on a preferred flextrack flightplan
2. Airline flight planning office recomputes optimum path based on latest winds
3. Airline sends new flight plan to the FMC via data link
4. Crew loads the flight plan and then transmits the new route to ATC and requests clearance
5. ATC clears via Two-way oceanic datalink (or VHF overland)
6. ATC monitors aircraft position using ADS

AirServices Australia (formerly CAA) is proceeding towards the full operational use of controller/pilot data link communications (CPDLC) and automatic dependent surveillance (ADS) for air traffic control. CPDLC will reduce the requirement for voice position reports and ADS will help reduce separation standards by giving controllers precise positions of aircraft in real time. Oceanic controllers will receive GPS derived position reports transmitted by satcom. Controllers then see a visual ‘radar-like’ display of, in this case part of the Australian FIR in the Pacific, displayed on Air Situation Displays. The information resembles the SSR display as seen on a normal radar screen; call sign, flight number, level etc. along with a projected track and forecast time of arrival at the next reporting point. When The Australian Advanced Air Traffic System (TAAATS) is fully operational, the CPDLC and ADS processing and display will be fully integrated with radar data processing and flight data processing and will provide a seamless transition as aircraft move from radar to non-radar covered areas. (AirServices Australia)

Aviation Authorities in the Pacific are gradually gearing up with their ground-based infrastructure. The South Pacific ATC centres controlled by the US (Oakland centre), Australia, New Zealand and Fiji have agreed to have ground systems certificated and operational by the end of 1995. Papua New Guinea, France (Tahiti/New Caledonia), and Singapore are also expected to support FANS-1 in the near future.

The ADS function of FANS gives controllers a three dimensional display in real time, similar to a conventional radar screen. This means controllers no longer have to mentally visualise their airspace aided only by random position reports and cardboard flight strips. As reported in AA (May ’95 Airspace Management), Airways Corporation of New Zealand’s Oceanic Control System was the first satellite based aviation navigation system to be introduced globally. The Canadian made equipment looks over the country’s 34 million square kilometre flight information region, which extends from the South Pole to the equator.

FANS will be an ongoing project well into the next century. Capt Massy-Greene’s involvement has mainly been in the en route aspect of the system. He said work still has to continue in the terminal area environment. “It’s no good flying halfway around the word on a flextrack, saving fuel only to be put in a holding pattern at your destination.”

One of the considerations associated with flight planning in the future, is the availability of alternate airports. GPS/FMS approach procedures are evolving, and will allow operations into airports which are normally not available to airlines. As the FANS-1 FMC will be certified to allow GPS only non-precision approaches to minimum descent altitude, more airports can be considered as alternates. There is also a fuel benefit with this practice.

The ‘F’ is slowly being removed from the FANS equation. FANS is predicted to become a sole system of ATM in only 15 years. The players in the FANS project, those keen to reap the benefits, are already talking about reduction in separation standards to 30nm (56km) laterally and 30nm (56km) longitudinally by April ’96 and reducing gate and taxi delays with GPS aided surface movement control.

Such procedure changes would be achievable with FANS-I and improved ground infrastructure. In practice more aeroplanes could fly at their optimum altitude and fly closer to preferred tracks achieving reduced flight time and fuel burn, reducing the cost of carrying contingency fuel reserves and increased payloads.

In short, FANS-1 enables operators to greatly increase revenues and reduce operational costs. The benefits are also crucial to national economies as they have the potential to increase their air transportation system capacity and reduce congestion.